Isolated hills or hill ranges rising abruptly from the plains are known as:

Inselbergs
Escarpments
Pediments
Plateaus

The correct answer is: A) Inselbergs.

Inselbergen (German for “island mountains”) are isolated hills or hill ranges rising abruptly from the plains. They are typically found in arid and semi-arid regions, and are thought to have formed by the erosion of surrounding land. Inselbergs are often home to unique plant and animal life, as they provide a refuge from the harsh conditions of the surrounding environment.

Escarpments are long, steep slopes that form the boundary between two landforms of different elevations. They are typically caused by faulting or erosion. Escarpments can be found in a variety of landscapes, including mountains, plateaus, and coastal areas.

Pediments are gently sloping surfaces that form at the base of mountains or hills. They are thought to be formed by the erosion of the underlying rock by wind and water. Pediments are often used for agriculture or grazing.

Plateaus are large, flat-topped areas of land that are elevated above the surrounding area. They are typically formed by the erosion of mountains or by the uplift of the Earth’s crust. Plateaus can be found in a variety of climates, including tropical, temperate, and arid.